Much has been done in golf club-head design in an effort to improve the performance of the golfer or otherwise enhance the golfing experience. Included in these efforts are methods and devices to assist golfers in proper aim to achieve consistent performance.
To achieve good results, many golfers find it desirable to have an alignment line (“sight line”) on the top of the surface of golf club-heads, including putters, to aid in aiming the ball as precisely as possible. The typical alignment line consists of a straight line or groove perpendicular to the putter face located precisely at the center of gravity of the club-head. U.S. Pat. No. 3,680,860, discloses that: “Putters and other golf club-heads have been known in the prior art to have alignment lines or other sighting marks. These alignment lines have generally been provided for the purpose of aiding the golfer in visualizing what was considered to be a proper straight-line path from the ball to the cup or target hole. The golfer was instructed to view the alignment line and then draw an imaginary extension from that alignment line through the center of the ball to the target. He would then attempt to hit the ball with a true linear stroke exactly in the direction of the target line toward the target.”
Other forms of alignment lines exist, including that described in U.S. Pat. No. 6,409,610, which includes both a perpendicular line and a curved horizontal face line which is an arc of a concentric circle of a golf ball placed abutting or one quarter of an inch in front of the hitting face of the putter. In all of these designs, however, the alignment line itself is a straight line intended to assist the golfer in aiming and swinging through on a linear path directly at the target. For those whose style dictates visualizing a pendulum style swing path, this form of sight line is generally acceptable. A number of patents provide for such sight lines, including U.S. Design Pat. Des. No. 264,367 to Gida and Des. No. 368,292 to Willoughby and U.S. Pat. No. 4,872,684 to Dippel. Other golfers rely upon multiple reference marks disposed on or around the club-head head in order to line up each shot. For instance, U.S. Pat. No. 4,805,922 to Whitfield; U.S. Pat. No. 4,861,038 to Fucinato and U.S. Pat. No. 5,692,969 to Schooler. Other clubs have been constructed having a central mark for aligning the putt and multiple other reference marks. For instance U.S. Design Pat. Des. No. 251,027 to Cruger, Des. No. 381,383 to Brett; U.S. Pat. No. 3,955,819 to Yokich show parallel white border grooves equidistant and on opposite sides of the red central groove and U.S. Pat. No. 5,746,664 Reynolds, Jr., claims a plurality of parallel sighting grooves disposed on the upper surface of the club-head.
For golfers who want to work not just on their aim, but also on their swing path or stroke, a number of training devices exist. Some may encourage a linear swing path, such as a simple string pulled taut between two posts under which a golfer may practice a straight back and through stroke. However, other devices exist which encourage a curvilinear club-head path. For example, a training device called “The Putting Arc” assists golfers on the practice ground in employing a swing path that curves in the same degree as the device. Golfers simply lay the device on the practice green directly adjacent to where they are stroking putts, and practice stroking along its curve. However, utilizing such a device on the course itself would be cumbersome and impractical, as well as in violation of the worldwide rules of golf as established by the United States Golf Association and the Royal and Ancient Golf Club of St. Andrews (See U.S.G.A. Rule 14-3). A similar putting aid is a device called the “Impact Trac” which is another visual tool laid on the surface of the green having a curved horizontal line to help the golfer guide a club-head through a curvilinear path in the hitting zone. A full swing aid along the same lines is a device called the Inside Approach endorsed by Jack Nicklaus, arguably the greatest golfer ever. This device is made of PVC Pipe that is partially covered by foam rubber. The device is placed next to the ball on the practice ground in such a manner that the golfer's club will strike the device if the golfer fails to swing the club-head on the proper curvilinear path.
The problem with the Inside Approach and other similar devices is that they are only training aids and cannot be used on the course during a regulation game, in addition to being too cumbersome and impractical to routinely take on the course. There clearly is a need in the art for a method and device to assist golfers during a regulation game in swinging the club-head on the proper curvilinear path. Currently existing sightlines do not follow a curvilinear path and therefore provide no help in visualizing and executing a curvilinear swing path. In fact, currently existing linear sightlines may actually distract from the natural and desirable tendency of golfers to swing along a curvilinear path. Thus, the present invention is designed to fill the need in the art for a method and device to assist golfers during a regulation game in swinging on the proper curvilinear path.